Trump still refuses to release his own tax returns as groups express concerns about the president eliminating the deduction for state and local taxes.

The president’s plan, released Wednesday, would eliminate the deduction for state and local taxes…

But the state and local groups said in a statement that the deduction should be preserved because it gives municipalities the flexibility to provide services to their residents…

The groups that issued the statement are: The National Governors Association, the National Association of Counties, the National League of Cities, the U.S. Conference of Mayors, the International City/County Management Association, the National Conference of State Legislatures and the Council of State Governments.

Trump’s plan is billed as “the biggest tax cut and the largest tax reform in the history of our country.” U.S. Treasury Secretary Steven Mnuchin said while unveiling Trump’s proposal that the president has no plans to release his long-sought-after tax returns — an issue that makes it easy for Democrats to oppose the proposal, reports CNN.